Last updated: Fri, 28 May 2010 17:35:52
It is now Wed, 13 Dec 2017 18:38:07

Insulin Syringes

31-gauge with half-unit markings

Kumbi's Favorite

BD Ultrafine II with half-unit markings

Originally posted Sunday, 9 May 2010; 13:26

[c104510cop-syrbox08.jpg] BD syringe box (side)

Kumbi and I love these syringes

Kumbi and I love these syringes. We started out with BD insulin syringes of 30-gauge, just because we didn't know any better, and the syringe barrels didn't have half-unit markings, either.

Bur our vets were prescribing dose changes of 0.25 units at a time - and I think it was our second syringe-purchase, when the pharmacist happened to hand me a box of syringes as shown in the picture above.

There's a larger picture that shows one of these syringes; it's the bottom one in the picture at Syringe Capacity. Ignore the other syringes pictured, and the cautions about conversion, because we are concerned here simply about choosing syringes for Novolin-NPH or Humulin-NPH, or other similar U-100 insulins.

Vekkie says, yes, you can use these syringes if you use her Novalin insulin, too.

Here you can see the half-unit markings

Though the half-unit markings are visible, you can't see the numbers on the barrel in this picture though the first digits of those numbers shows.

Entire syringe

[c104344cop-bd310cc16.jpg] Half-unit markings on barrel

I use a magnifying glass

Even with the half-unit markings, I find I need to use a hand-held magnifying glass to make sure I get the dose right. That's especially true if I'm working with quarter-units, as often enough, I am doing!

It's really useful, when working with U-100 insulin with small dogs, to be able to adjust by quarter units.

I do need to handle these 31-gauge needles with care, because they do bend fairly easily. But if I merely pay attention to how I'm handling them - if I avoid putting sideways pressure on them, when drawing insulin, or - when shooting Kumbi in the back! - I can avoid bending the needles.

My buddy Eileen reports on Walmart ReliOn syringes

Quoted with permission from Eileen; copyright 2010 by Eileen.

Slightly edited for the web

Eileen reports, on the k9 diabetes forum, that the ReliOn syringes sold at Walmart, of the same capacity as the BD syringes I show here (0.3 cc; 31-gauge, short needles [8mm, which is 5/16-inch]), also have the half-unit markings. She has been using these for some time, with good results. The huge advantage of using the ReliOn syringes is - their price!

"When it comes time to buying syringes I would go with Walmart's ReliOn brand - 0.3 cc, 31-gauge, 5/16ths needle WITH half unit markings. Having the half units marked on the barrel helps tremendously when/if it ever comes time to use smaller fractions.

"The 0.3cc syringes hold up to 30 units of insulin and are much easier to handle than larger 1/2 or 1 cc syringes.

"They run $12.58 for a box of 100."

Close-up view of half-unit markings

[c104507cdop-bd310cc19.jpg] Close-up, plunger at two units

Kumbi and I dedicate this picture to Fergy and Harry.

I see I left a drop of water on the outside of the needle-holder. That was a used syringe I took the pictures of - I can't afford to be wasting syringes! But I rinsed the syringe before shooting it.

I am so kind.

There WAS the time that we ended up with a very bent needle and neither Kumbi nor I know how that happened!

A few barrel-marks, for conversion?

[c104507cdop-bd310cc114.jpg] Berrel-marks at 5, 6, 6.5, 7

Considering measuring Caninsulin in a U-100 syringe

Kumbi and I dedicate this picture to Alfie and Allison.

This is MY wild idea, nothing to do with Allison nor Alfie, really, because I'm not at all sure this would work for them.

It LOOKS as though maybe Alfie needs between 2.5 and 3 units of Caninsulin. But 3 units caused problems. And with 2.5 units, Alfie is running high. So, even though I'm totally impossible with numbers, I personally am thinking about whether Allison could measure a dose of 2.75 units of Caninsulin.

It seems to me next to impossible to do that using a Caninsulin syringe, just because the markings on the barrel aren't fine enough.

What follows may be mostly nonsense, as I'm not sure, if we make the necessary conversion, to measure, say, 2.75 units of Caninsulin (which is a U-40 insulin) in a syringe intended to deliver U-100 insulin, we could actually measure it in any reasonable or useful way.

I have my doubts!

To convert - to find the barrel-mark on the U-100 syringe you would need to measure to, to deliver Caninsulin (or any other U-40 insulin) from a U-100 syringe, you would need to multiply the number of units (of the U-40 insulin) by 2.5. So, let's experiment a bit -BUT NOT ON ALFIE! - just in pictures.

To deliver 2.5 units of Caninsulin in a U-100 syringe, you would need to measure to the barrel-mark numbered (2.5 x 2.5), or, 6.25. There IS no such marking, though the syringes I use do have half-unit markings. And in fact, I do measure to quarter-units myself, for Kumbi, by using a magnifying glass and getting about halfway between the half-unit markings.

To measure 3 units of Caninsulin in a U-100 syringe, we have (2.5 x 3.0), or, 7.5, so we would use the 7.5 barrel-mark on the U-100 syringe - that wouldn't be all that difficult, on a syringe that HAS such markings; and the ones shown on this page do have them.

But what happens with 2.75 units of Caninsulin - if we attempt to measure that in a U-100 syringe? Well, we'd be aiming at (2.5 x 2.75), or, 6.875. NO WAY do we have such markings on these U-100 syringes. How about 6.8? That's not marked, either. Or 6.9? THAT is not marked EITHER! Well, then, how about measuring to the 7.0 mark,, and then extruding a drop of insulin from the syringe before injecting? Well, THAT might actually work!

Whether it makes sense to go through such a hassle, I'm not sure.

It's inherently very risky to use the wrong syringes

A person who decides to use U-100 syringes with U-40 insulin MUST be constantly on the alert, and be absolutely sure, when conversing or exchanging records with veterinarians, to distinguish between actual units of insulin (here, it would be, say, 2.75 units of Caninsuln), and the mark on the barrel to which the dose is measured in a U-100 syringe. So, to protect a dog being shot with the wrong syringes, the insulin-delivering human MUST remember to talk about units of Caninsulin, but about "barrel-marks," when referring to the measurement on the barrel of the U-100 syringe.

The Great Outside

DISCLAIMER: Contents on Vekkie's Playground are almost entirely fantasy. Do NOT try to make your own insulin. Obtain what your veterinarian prescribes for your animal, and use that. For any questions about insulin or its measurement and dosage, consult your veterinarian. And do not try swinging from clocks.